Process of separating nickel and cobalt



v UNITED STATES PATENT OFFICE.

MARVIN J. UDYaOF KOKOMO; INDIANA, AND OLIVER C. RALS'I'ON, OF NIAGARA FALLS, NEW YORK, ASSIGNORS TO EOOKER ELECTROCHEMICAL COMPANY, 01 NEW YORK, N. Y., A. CORPORATION OF NEW YORK.

PROCESS OF SEPARATING NICKEL AND COBALT.

No Drawing.

tion of nickel and cobalt from solutions of' their mixed salts.

It is known that a certain separation as between nickel and cobalt may be accomplished by the use of hypochlorite solutions, by which cobalt is oxidized to the cobaltic state .and precipitated in the form of a black oxid, most of the nickel remaining in solution. In the practice of such process, it is necessary however to maintain a very close control of the operating conditions, particularly as regards the alkalinity and temperatui'e of the hypochlorite solution moreover the separation is incomplete, some nickel being always, present in the cobalt precipitate and usually some cobalt in the nickel solution. l

We have discovered that a better separation of these metals may be accomplished by treating solutions containingnickel and cobalt, but preferably free from iron, with calcium carbonate or its e uivalents and chlorin in excess. At relatlvely lowtemperatures (preferably about zero to 40 C.) the cobalt is practically quantitatively .precipitated upon the excess of carbonate, while substantially the whole of the nickel remains in solution.

The method is sufliciently exact forv use in the uantitative determination of nickel and cobal industrial separation and recovery. E1ther sulfate or chlorid solutions may be used, the latter being usually preferred.

For example, in the application of the method to the treatment of nickel-cobalt ores of the type found in the cobalt district of Canada, the metal values are first brought into solution in the form of chlorids by any approved method. Iron is removed by treating the, solution with chlorin, removing the excess of chlorin by means of air or other- Specification of Letters Iatent.

t, and it is likewise applicable to their.

Patented Jam 11, 1921.

Application filed July 3, 1919. Serial No. 308,389.

wise, and then agitating with calcium carbonate or similar precipitant. If the chlorin has been completely removed the iron only is precipitated. The resulting solution, containing nickel and cobalt, but free from 1ron, is then mixed with finely divided calcium carbonate and gaseous chlorin is bubbled through the pulp. If the solution is kept at a sufficiently low temperature, very ure black cobalt oxid is formed, and practically all of the nickel remains in the solution. All hi her temperatures some nickel is also precipitated.

The reactions involved in the separation are not certainly known, although there is reason to believe that a cobaltic salt is first formed and thereafter hydrolyzed, the cal-- The nickel may be recovered from the solution in accordance with any approved method. The cobalt isobtained as oxid in admixture with the excess of-carbonate and v may be separately recovered by any appro- 2. Process of preci itating cobalt from mixed nickel-cobalt so utions, comprising s1- multaneously subjecting the solution to the MARVIN J. UDY. OLIVER C. RALSTON. 

